Executions in California, halted by court order since 2006 because of questions about the state's lethal injection procedures, will remain on hold until at least late next year, court filings disclosed Thursday.

State prison officials have been trying to revise and win judicial approval for their execution methods since a federal judge blocked the February 2006 execution of Michael Morales, convicted of raping and murdering a Lodi teenager in 1981.

U.S. District Judge Jeremy Fogel ruled later in 2006 that deficiencies in staff training, supervision and procedures for preparing and administering the lethal chemicals had created an undue risk of a botched execution that would leave the inmate conscious and in agony while dying.

Since then, the state has rewritten its rules, upgraded its training, and built a new execution chamber at San Quentin State Prison. Their efforts were set back when state courts ordered them to seek additional public comment on the changes and when the sole U.S. manufacturer of one of the drugs ceased production. That forced California and other states to seek foreign supplies and prompted further questions about quality control.

On Thursday, Seeborg approved a timetable proposed by lawyers for the state and condemned prisoners. The timetable gives them until mid-September 2012 to collect and exchange evidence and request a hearing on whether the new procedures contain adequate safeguards, as required by the constitutional ban on cruel and unusual punishment.

The order extends the previous schedule by seven months. Even if Seeborg ruled in the state's favor, appeals to higher courts would almost certainly delay the next execution until 2013. California has 718 condemned prisoners, more than any other state. Morales and three others who have also exhausted their appeals are plaintiffs in the court case.